The present invention relates to a rolling bearing unit with a sensor for use in the rotation support part of a machine which, when a large load is applied thereto to thereby damage the bearing thereof suddenly, requires a lot of labor and time to replace the damaged bearing with a new one, or for use in the rotation support part of a large-sized machine which includes a large number of rotation support parts and thus needs to control the starting times of use of the respective bearings, such as the rotation support part of a rolling roller used in a rolling mill for iron and steel or the rotation support part of various rollers used in a paper manufacturing machine.
For example, in the case of a rolling bearing to be used in the rotation support part of a machine which, in case where a large load is applied thereto to thereby damage its bearing unexpectedly, requires a great deal of labor and time to recover the damaged bearing such as a rolling bearing for supporting a roller neck for supporting the rolling roller of a rolling mill for iron and steel, it is necessary to prevent such unexpected damage of the bearing. For this purpose, generally, when such rolling bearing is used, not only the vibrations and temperatures of the rolling bearing in operation are measured but also whether an abnormal condition has occurred in the rolling bearing or not is checked in accordance with the thus measured vibrations and temperatures. For example, conventionally, in order to detect the occurrence of the abnormal condition in the rolling bearing, not only a vibration sensor consisting of accelerometer and a temperature sensor consisting of a thermocouple are mounted on part of a housing for storing the rolling bearing therein, but also these sensors are connected to an output apparatus disposed externally of the housing by wires such as a harness. And, when such rolling bearing unit with sensors is in use, the vibrations and temperatures of the rolling bearing are measured by the sensors indirectly through the housing. And, not only the vibrations and temperatures of the rolling bearing detected by the sensors are compared with their respective preset given threshold values for each passage of a given time in the above-mentioned external output apparatus, but also, in case where the detected vibrations exceed their threshold values, an effect telling the abnormal condition of the rolling bearing is output to the output part of the output apparatus to thereby notify an operation manager of the abnormal condition of the rolling bearing.
Also, in the case of a rolling bearing to be used in the rotation support parts of a large-sized machine which includes a large number of rotation support parts, the conditions of use of the respective rolling bearings thereof are different and, therefore, the lives of the respective rolling bearings vary from one another. Therefore, in case where the machine is used while replacing these rolling bearings, the starting times of use of the respective rolling bearings are different. Accordingly, in such large-sized machine, it is necessary to manage the starting times of use and using conditions of the respective rolling bearings. And, in order to manage such use starting times and using conditions, conventionally, when an operator assembles the respective rolling bearings onto the rotation support parts, the operator inputs the use starting times of the respective rolling bearings, the identification marks thereof, the assembling positions thereof, the numbers of housings and rollers to which the respective rolling bearings are assembled, and data on the accuracy of the respective rolling bearings into a computer, or writes them down in recording paper by hand. Since the lives of the respective rolling bearings can be predicted to a certain degree from the data on the use starting times of the respective rolling bearings, in case where such data are managed, it is possible to replace the respective rolling bearings before their lives are over.
In the above-structured conventional bearing unit with sensors, there are found the following problems to be solved.
(1) Since the sensors mounted on the housing are connected to the output apparatus by wires such as a harness, when replacing the rolling roller which needs to be replaced relatively frequently, the harness provides an obstacle, so that the operation to replace the rolling roller becomes troublesome.
(2) Because the vibrations and temperatures of the rolling bearings are measured indirectly through the housing, it is necessary to improve not only the measured values of the vibrations and temperatures but also the accuracy of the detection of the abnormal conditions of the rolling bearings based on such measured values.
(3) The operation for the operator to input the data on the use starting times of the respective rolling bearings or write down them into the recording paper is executed at a timing different from the assembling operation of the respective rolling bearings and at a place distant from a place where the assembling operation is carried out. This can raise a possibility that the data can be recorded wrong. However, it is troublesome to record the data while paying attention so as not to record the data wrong.